Want Your Baby to Recognize You? Stand on Her Left

You already knew this, but your newborn baby is super smart. But now there’s more evidence as to exactly how (and how quickly) she’s taking in the world around her: According to a quirky new study published in the journal Nature Human Nature, babies are more likely to recognize faces when they pop up on their left side.

What we know about the brain & babies

Faces are one of the first forms that babies recognize; doing so it’s an important part of social bonding. Incredibly, starting at birth, babies are able to distinguish their mom’s face from a strangers, mostly by looking at the shape and the hairline — although they have trouble recognizing mom’s face from even a slightly profile view. However by about 4 to 5 months old, babies are able to recognize a growing number of new faces, even when they see them from different angles. They’re also better able to recognize faces of the ethnicity and sex that they interact with the most.

Past studies have shown that early on in life, babies are more adept at using the right hemisphere of their brains. The right hemisphere of the brain controls the left side of the body; the left hemisphere controls the right side of the body. Both sides of the brain work together, however, in processing information, including visual info. During the first year of life, a baby’s neural connections between the two sides of the brain strengthen as baby’s brain rapidly develops and grows.

In adults, the reaction times for recognizing faces that pop up on the left side are slower than those seen from the right side and thus are processed by the right brain. Past studies have actually already found that babies are also better at recognizing faces in their left field of vision, but researchers weren’t able to determine whether it’s because both sides of the brain are working together but the left side is faster, as is the case with adults — or whether only the right hemisphere performs the task, which is "radically different" from how adult brains work.

What the study looked at

In this study, researchers were interested at looking into how babies brains’ processed visual information in the most familiar territory — faces. They recruited a group of 40 babies between the age of 1 and 6 months old. Using brain imaging techniques (MRI and EEG), they first explored the connectivity of the two sides of babies’ brains. Then they assessed how good each side of the brain was at discriminating a face presented on the left side or the right side to determine if both sides of the brain are responding to a new face or just the right hemisphere.

What it found

The researchers found that in babies, the right hemisphere of the brain (but not the left) recognizes faces perceived by the opposite (left or right) eyeball. Within the first few months of life, the right brain became better at recognizing faces, whereas the left brain remained unresponsive to facial differences. What’s more, faces viewed from the right side — which are processed by the left side of the brain — did not evoke a strong response in either the left or right side of the brain, showing that the two sides of the brain are still learning (and not yet all that good) at communicating in young babies. However, within the first few months of life, the left and right sides of the brain became increasingly interconnected and more efficient at sharing information.

What this means for you

While there’s not really any next steps for parents to take away from this study, it does highlight how incredibly complex and amazing your little one’s brain is from such a young age. As an infant, your baby’s brain is already organized to assign different tasks to different parts the brain — and those connections develop rapidly in a short amount of time. All the more reason to keep reading, snuggling and playing with your little one. She’s soaking every last bit in!